21401420144 has 40 divisors (see below), whose sum is σ = 46596413472. Its totient is φ = 9448116480.

The previous prime is 21401420143. The next prime is 21401420177. The reversal of 21401420144 is 44102410412.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401420143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2231987 + ... + 2241554.

Almost surely, 2^21401420144 is an apocalyptic number.

It is an amenable number.

21401420144 is an abundant number, since it is smaller than the sum of its proper divisors (25194993328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21401420144 is a wasteful number, since it uses less digits than its factorization.

21401420144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4473585 (or 4473579 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 21401420144 its reverse (44102410412), we get a palindrome (65503830556).

The spelling of 21401420144 in words is "twenty-one billion, four hundred one million, four hundred twenty thousand, one hundred forty-four".